Some walls are all length and no height: the strip above a sideboard, the run along a corridor, the band between a door frame and the ceiling. The question they raise is not how many frames will fit — plenty will — but what proportion the finished row should have. Get that ratio wrong and a perfectly measured arrangement still reads as a stripe of postage stamps.
Keep the row between 2:1 and 3.5:1
Measure the total span of the arrangement against its tallest frame. That ratio is what decides whether the row looks like a considered band or a thin line pinned across the wall.
| Total span | Tallest frame | Ratio | Reads as |
|---|---|---|---|
| 120 cm | 42 cm | 2.9:1 | A band — right |
| 200 cm | 42 cm | 4.8:1 | A stripe — too thin |
| 200 cm | 70 cm | 2.9:1 | A band — right |
| 240 cm | 100 cm | 2.4:1 | A block — right, but assertive |
| 300 cm | 70 cm | 4.3:1 | Too thin — split it |
There are three ways out of a ratio above 3.5:1. Go up a format. Add a second row, which doubles the height at a cost of 5 cm for the gap. Or split the run into two groups separated by a deliberate pause of 40 to 60 cm, which resets the ratio for each group and reads as intentional in a way that one over-long row never does. Format dimensions are in the poster size guide.
Above a sideboard, the furniture caps the format
The standard centre height of 145 cm assumes empty wall below. Over a sideboard it collides with the furniture, because the bottom edge of a tall frame drops behind the top of the unit. Keep at least 15 cm of clear wall between the top of the sideboard and the bottom of the frames.
| Sideboard height | Tallest frame at a 145 cm centre | Largest format that works |
|---|---|---|
| 75 cm | 110 cm | 70×100 |
| 80 cm | 100 cm | 70×100, exactly at the limit |
| 85 cm | 90 cm | 50×70 |
| 90 cm | 80 cm | 50×70 |
Note that 100×140 never appears. Centred at 145 cm its bottom edge sits at 75 cm, which is below the top of almost any sideboard. It is a floor-leaning or empty-wall format, not a furniture format. The height rule itself is set out in the 145 cm rule explained.
Winnie Møller - Fantasi i Himlen 1
Winnie Møller - Skovens Blomster 1
Cat in Window Poster
Yayoi Kusama - Red Dots Poster
Meeting at Sunset - Vincent V
Tree of Life - Thomas Nordentoft
Span two thirds of the furniture, not two thirds of the wall
Where there is furniture, it governs. A 180 cm sideboard wants a span of about 120 cm even if the wall runs to four metres — the arrangement belongs to the unit below it, and letting it overhang the ends breaks that relationship. Where there is no furniture, as in a corridor, the wall governs and 60 to 70 per cent of its length is the target.
Landscape formats earn their place here
This is the one situation where turning frames on their side is more than a preference. A 30×42 hung landscape is 42 wide and 30 tall, which pushes span up and height down — precisely the wrong direction on a long wall. Portrait orientation is usually the correct instinct for a narrow run, with landscape reserved for a single anchor piece in the middle.
The exception is the very low band above a doorway or under a sloping ceiling, where height is not available at all. There a row of landscape 21×30 at 21 cm tall is the only thing that fits, and the honest answer is to use three or four of them rather than nine — a short row of small frames looks deliberate, a long one looks like a border.
Twelve layouts with finished dimensions are in the gallery wall guide, motifs for corridors are in the collection for the hall, and for a sideboard in the main room, the posters for the living room.